The Influence Of Aftertreatment On Use Property Of Polyester Woven Filter-cloch

Polyester woven filter fabric is the most commonly used filter media with high strength, good abrasion resistance, adjustable filtration precision in a large range, and etc. The shrinkage of polyester woven fabric will cause many problems in the application, especially in the large box-type filter press. To improve the dimensional stability (non-shrinkage under high temperature), filter fabric requires aftertreatment (a heat-setting process). Therefore, the influence of heat-setting on application properties of polyester woven filter fabric was studied.The effects of heat-setting process on physical and mechanical properties, permeability, pore diameter, dimensional stability and crystallinity of polyester filter fabric were explored. The relationship between heat-setting conditions and application properties are discussed. Moreover, the optimum conditions were determined.The analysis of effects of heat-setting time, temperature and tension on dimensional stability, breaking strength, permeability, pore diameter and crystallinity indicated that heat-setting temperature is the prominent factor. Below the melting temperature of polyester (255℃), the crystallinity, crystal size and crystalline perfection increased with the increment of heat-setting temperature. Desirable dimensional stability can be acheived when heat-setting temperature is20～30℃higher than application temperature. Furthermore, with heat-setting temperature increasing, permeability and equivalent pore diameter decreased. Finally, the regression model of twill polyester woven filer fabric was built through quadratic regression orthogonal design. It can be obtained that the permeability reached a minimum value at heat-setting temperature of218℃, time of141s and tension of10T.The research of this subject provides the theoretical basis and data reference for selection and manufacture of filter fabric. The reasonable heat-setting process can be selected according to the regression equation to obtain required mechanical strength, dimensional stability, permeability and equivalent pore diameter, which benefits the energy-saving and low-cost selection and development of filter fabric.